A conventional faucet seals up water flow by means of a rotating valve stem to closely oppose a water seal packing against an inlet pipe of a faucet casing. The water seal packing suffers from the water pressure as well as the twisting stress applied by the valve stem, and is apt to be distorted and worn out. Additionally, a water seal ring must be disposed on the joint between the valve stem and valve cap to prevent leakage. Such a water seal ring is also easily damaged due to rotation of the valve stem. Therefore, leakage is often found in the above two places of a conventional faucet.
While a water pressure-sealing faucet applies water pressure itself to seal up water flow, and thus the water seal packing thereof stands much smaller stress and is not so easily worn out. Furthermore, the valve stem of a water pressure-sealing faucet only linearly slides without rotation. Thus, the water seal ring disposed around the valve stem bears smaller frictional force and performs desirable sealing function during a longer period of time.
However, not like a conventional faucet the water pressure-sealing faucet as described above shuts off water flow so quickly that the running water flow stops abruptly to cause considerable water hammer effect, which greatly tends to damage the water pipe line.
Therefor, a water pressure-sealing faucet without water hammer effect is needed to eliminate the aforesaid disadvantages.